Embodiments of the disclosed technology related to an electrode plate for external electrode lamp and a backlight.
The structure of an EEFL (External Electrode Fluorescent Lamp) is shown in FIG. 1. In FIG. 1, there is no electrode within the EEFL which comprises a glass tube 1 and metal electrodes 2 at both ends of the glass tube 1. Inert gas 3 is sealed in the glass tube 1, the inner wall of which is coated with fluorescent powders.
During operation, a high-frequency voltage applied across the external electrodes 2 is introduced into the glass tube 1 of the EEFL by capacitive coupling to excite the inlet gas and release energy. As a result, the energy released by the inlet gas raises atoms of the fluorescent powders on the inner wall of the glass tube 1 to a higher energy level. Visible light is emitted when the excited atoms return to the initial lower energy level.
Another type of EEFL is formed by modifying an existing internal electrode fluorescent lamp. External metal electrodes are provided to both ends of the existing internal electrode fluorescent lamp and connect to the internal electrodes. In this case, a high-frequency voltage applied across the external metal electrodes is directly coupled into the glass tube by electrical conduction.
The conventional method of fixing EEFLs which are adapted as light sources in a backlight is performed as follows. A plastic plate or a printed circuit board used as a base is placed onto the back plate (or frame) of the backlight; pairs of opposing electrode sockets are provided for mounting the EEFLs, and the sockets comprise an inside conductive structure and an insulating package; and each EEFL is directly plugged into one pair of electrode sockets. However, since the structure of the electrode sockets is quite complex and the cost of making the electrode sockets is quite high, the cost of fixing the EEFLs is too high.